(wildlife chirping) - [Narrator] It's a pygmy marmoset.
Weighing less than an apple, pygmy marmosets are the smallest monkey in the world.
- Look at their little faces.
(camera whirring) - [Narrator] Their needle-sharp fingernails enable them to scamper up and down tree trunks and vines, leaping over 30 times their body length from tree to tree.
They can swivel their heads backwards to spot any potential predators.
(marmoset squealing) And it seems something has caught the eye of one of the marmosets, prompting a loud warning call.
- Oh, look, he's really nervous.
He's looking around.
- There's some movement over there.
- [Narrator] The technology we're using here means we have an eye at all levels of this jungle.
- Zoom in there?
- [Narrator] From one of our canopy cameras, we can zoom in and see what's triggered this alarm, a great black hawk stealthily eyeing them up, a very real threat for one of these snack-sized monkeys.
(marmoset squealing) The shrill call lets the hawk know he's been spotted.
And it has the desired effect.
His cover has been blown, and he's lost the element of surprise, allowing the rest of the marmosets to return to their playful ways for now.